Currently, digital image capture devices such as digital cameras and camera phones are widely used to take photographs. Referring to FIG. 1, a schematic block diagram of a conventional digital image capture device is illustrated. The digital image capture device 100 comprises an image signal generator 110 and a display screen 120. When an activating button is clicked to take a photograph, the image of an object is generated by the image signal generator 110 and transmitted to the display screen 120 for display.
As known, there are two approaches to evaluate whether the images are sharp or not.
In accordance with the first approach, the image of the object taken by the digital image capture device 100 is immediately shown on the display screen 120 such as a liquid crystal display (LCD). By successively scaling up and shifting the image, the user may visually discriminate whether the image is sharp. If the image is blurred, the use may retake the photograph as desired. This approach, however, is time-consuming and consumes much power.
In accordance with the second approach, the image of the object taken by the digital image capture device 100 is transmitted to a computer and shown on a monitor (not shown). Likewise, the user may visually examine the image shown on the monitor to discriminate whether the image is sharp. Since the computer's monitor is much larger than the display screen 120 of the digital image capture device 100, the procedure of successively scaling up and shifting the image may be exempted. Unfortunately, if the image is considered as a blurred image at this time, the chance of retaking the photograph is lost. As a consequence, the first approach is acceptable for most users.
Recently, some digital image capture devices have built-in anti-shake video compensation systems to implement quality automatic retouching and enhancement so as to retouch and enhance the quality of the image. The digital image capture device with the capability of quality automatic retouching and enhancement is more expensive than that without the quality automatic retouching and enhancement. In views of cost-effectiveness, the anti-shake video compensation systems are not suitable to some kinds of digital image capture devices such as camera phones.
In views of the above-described disadvantages of the prior art, the applicant keeps on carving unflaggingly to develop a method for blurred image judgment according to the present invention through wholehearted experience and research.